Testing for and identifying materials in fluid media is becoming increasingly important in various fields such as medical and pharmaceutical research and development, food preparation, environmental studies, and other similar fields. Typically, these fields require the detection of materials such as contaminants, pollutants or other foreign objects in a fluid such as a gas or liquid.
One common type of detection device is an optical sensor. Light is a useful tool in identifying materials in a liquid or gas. Typically, light is emitted at a particular wavelength and directed through the liquid or gas to a detector where the light is collected. Materials in the liquid or gas can cause a disturbance or change to the wavelength or other measurable characteristics of the emitted light. Methods such as Raman scattering analysis (i.e., analyzing scattering patterns of protons), absorption analysis, fluorescence analysis, plasmon analysis (i.e., analysis of plasma oscillation), and Fourier transform infrared spectroscopy (FTIR) are commonly used to determine or identify any materials in the liquid or gas.
In most applications, a detection device is precisely configured to detect materials at very low concentrations. Detection devices incorporating optical sensors have been proven to reach the desirable detection levels. However, it is a challenge to produce an integrated, low-cost optical sensor capable of reaching the desired detection levels. Often, the creation, delivery and detection of light require large apparatuses which are not amenable to size or cost reduction.